Classifications

• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23J—PROTEIN COMPOSITIONS FOR FOODSTUFFS; WORKING-UP PROTEINS FOR FOODSTUFFS; PHOSPHATIDE COMPOSITIONS FOR FOODSTUFFS
  • A23J3/00—Working-up of proteins for foodstuffs
  • A23J3/04—Animal proteins
  • A23J3/08—Dairy proteins
  • A23J3/10—Casein

Definitions

• the present invention relates to a process for preparing a heat resistant milk protein having good processability and/or acid- and base- resistance. More particularly, it relates to a process for preparing a milk protein which has enough heat resistance to prevent the heat softening properties of caesin (which is a main component of milk protein) as well as such good processability that it can readily be made into a desired shape, and hence, is useful as a raw material for food, and the present invention also enables the production of a milk protein which is resistant to acids and bases and is useful as a raw material for food and as or in a food additive.
• a process for preparing a milk protein resistant to acids and bases which comprises subjecting an aqueous solution or dispersion containing casein and 0.5 - 30 parts by weight (the term “parts” hereinafter means “parts by weight”) of an acidic polysaccharide per 100 parts of casein to heat treatment at pH 7.3 to 10.5 and at a temperature of not less than 70 0 C for 3 minutes or more.
• the thickening activity of the resulting milk protein can be further improved by carrying out the heat treatment in the presence of calcium ion or magnesium ion.
• the present invention also permits the provision of a casein having good heat resistance and also enables the preparation of a milk protein which has an excellent processability.
• an aqueous solution or suspension containing casein and 0.5 - 20 parts by weight of an acidic polysaccharide per 100 parts of casein may be subjected to heat treatment at pH 7.5 to 10.5 and at a temperature of not less than 70 C for 5 minutes or more, and the resultant material thereafter formed into a desired shape, and then the thus-shaped material soaked in an aqueous solution containing a multivalent metallic compound in an amount of 10 mM or more as multivalent metal to provide heat resistance to the casein.
• an aqueous solution or dispersion of casein and an acidic polysaccharide is first prepared.
• the acidic polysaccharide may be, e.g., alginic acid, sodium alginate, alginic acid propylene ester, carrageenin (any one of K , A and ⁇ .) or furcellaran.
• Other polysaccharides which may be employed in the invention are gum karaya, gum ghatti, gum tragacanth, xanthan gum, methyl cellulose, carboxy methyl cellulose or low-methoxyl pectin. They can be used alone or in a combination thereof.
• the acidic polysaccharide is used in the ratio of 0.5 - 30 parts per 100 parts of casein to achieve acid- and base- resistance. When this ratio of the acidic polysaccharide to casein is either too small or too large, the desired resistance to acids and bases is not to be expected.
• the aqueous solution or dispersion can be prepared by dissolving or dispersing casein and an acidic polysaccharide simultaneously or successively in hot water or the above aqueous alkaline solution according to a conventional manner. Alternatively, it can be prepared by separately dissolving or dispersing casein and an acidic polysaccharide in advance and then mixing them.
• other ingredients for example, a neutral saccharide such as glucose, sucrose or starch, oils and fats and the like, may be added to this aqueous solution or dispersion.
• casein and the acidic polysaccharide form a complex and, thereby, the desired resistance to acids and bases is provided.
• a desired change in the configuration of the casein results by subsequent treatment with a multivalent metallic compound providing heat resistance to the casein.
• the pH of the heat treatment must be, as described above, in the range from 7.3 to 10.5, e.g. 7.5 to 10.5.
• the heat treatment is preferably carried out at 70 - 130 0 C for up to 90 minutes, e.g. 5 to 90 minutes in view of operational and economic efficiency.
• the thickening activity of casein is further improved.
• a calcium ion source or a magnesium ion source prior to or during the heat treatment.
• the calcium or magnesium ion source there can be used e.g. calcuim chloride, calcium phosphate, calcium carbonate, calcium sulfate, calcium lactate, calcium hydroxide, magnesium chloride, magnesium sulfate, magnesium citrate and/or magnesium lactate.
• the calcium or magnesium ion source can be used in a ratio of 0.1 to 1.4 parts per 100 parts of casein calculated as calcium or magnesium ion. When this ratio is too high, the thickening activity is rather spoiled.
• casein solution was prepared by dispersing 100 g of casein in 400 ml of warm water and then adding 5 ml of 28 % aqueous ammonia to dissolve casein. 50 ml Portions of this casein solution were respectively added to the beakers A, B and C, and the mixtures were thoroughly stirred and then pH's thereof were adjusted to 9.0 with 1N sodium hydroxide. Then, each beaker was heated at 80 °C for 30 minutes after which each solution was added to 10 % aqueous calcium chloride via a 10 ml pipette, and their appearance observed. The results were as follows:
• a solution (pH 8.0) composed of 10 kg of casein, 0.5 kg of carrageenin, 40 kg of warm water and 0.33 kg of sodium hydroxide was divided into seven equal portions. Calcium chloride was added to each portion of the solution in such an amount so as to provide 0, C.35, 0.37, 2.5, 5.1, 5.2 or 8.0% by weight based on casein respectively.
• Each solution was heated at 80°C for 15 minutes and then immediately cooled. The cooled solution was appropriately diluted and spray-dried. 100 g of each powder thus obtained was dissolved in 400 ml of warm water or a 5 % aqueous solution of sodium chloride and distributed into 50 ml beakers. They were cooled to 5°C.
• Example 2 The same procedure as in Example 1 was repeated except that the amount of c-carrageenin was decreased to 0.2 kg or the heat treatment was carried out at pH 7.0 tc obtain respective milk protein powders.
• a cream was produced by using each milk protein powder thus-obtained.
• fat was aggregated at 40°C and the cream was separated into an aqueous layer and an oil layer by further elevation of the temperature.
• aggregation of fat spheres was observed.
• the milk protein showed an appearance and texture similar to Yuba (skin of boiled soy milk).

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• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
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• Health & Medical Sciences (AREA)
• Nutrition Science (AREA)
• Biochemistry (AREA)
• Engineering & Computer Science (AREA)
• Food Science & Technology (AREA)
• Polymers & Plastics (AREA)
• Dairy Products (AREA)
• Peptides Or Proteins (AREA)
• Jellies, Jams, And Syrups (AREA)

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• 1985
  • 1985-09-04 EP EP85306286A patent/EP0174192A3/de not_active Withdrawn

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